Time is about to run out for Joseph Miller. The ex-marine is being stalked in his retirement by a twisted serial killer with a flair for the theatrical: The Holy Ghost. When the spectre strikes again, Miller becomes the sixth in a chain of grisly murders going back decades. Detective Tom McHale is brought in to lead the investigation, having already put away a multiple murderer. His reputation is on the rise, and an autoimmune disease and self-medication don't dull his edge. To hunt The Holy Ghost, McHale enlists the help of a Native American FBI agent, a Jesuit priest, and a powerful supercomputer named Mother. Together, they form a formidable alliance that will stop at nothing to track down the killer and bring him to justice. But time waits for no-one, and as the hour approaches, the seventh victim could be closer than they think.